A toggle is a switch that has two positions: on and off. They are often found in hardware devices, like a keyboard’s Caps Lock and Num Lock keys, as well as software, like options menus.
The word toggle comes from the 18th century, when it was used for a fastener that pins through the eye of a rope to secure something to the other end. It is also used in the verb to toggle, which means to change from one state to another.
When designing a toggle, consider the context and visual design. For example, use a high-contrast color to signal a state change. This helps users understand what’s happening without having to look at the button itself.
In addition, ensure that the state descriptors—On and Off—are included. These descriptors provide clear visibility of the system status and can help users avoid confusion if they aren’t familiar with your system.
Feature Flag Management and Testing
When a team has a large number of toggles, it can be challenging to manage toggle configuration. Many teams move toggle configuration into a centralized store where it can be accessed and modified by system operators, testers and product managers.
Savvy teams see toggles as inventory that come with a carrying cost and seek to keep their toggle inventories as low as possible. They regularly remove toggles that are no longer needed and they place “expiration dates” on them.
Some feature flag systems support runtime re-configuration, which can make it easier to update toggles in-memory during testing. This can significantly reduce the need for developers to restart or re-deploy an artifact during testing, which in turn improves the CI/CD cycle time.